Sudden-death link to heart valve prolapse

Researchers have linked sudden cardiac death — when the heart suddenly stops beating — with a common condition, a significant breakthrough.

Academics across four states analyzed more than 7600 studies and found 12 percent of people who suffered sudden cardiac death without a clear cause had mitral valve prolapse.

A prospective Australian registry for patients with the condition, as well as those resuscitated after cardiac arrest and reported sudden cardiac deaths, is being created by researchers and cardiologists from the universities of Adelaide, Melbourne, NSW, and Queensland.

Prash Sanders, director of the centre, said one in five sudden cardiac deaths occurred in people with otherwise normal hearts.

Sudden cardiac death differs from a heart attack because it is caused by an “electrical malfunction” rather than blood-flow problems.

About 12 in every 1000 people suffer from mitral valve prolapse, which does not allow the “leaflets” of the valve that let blood flow from one chamber to another to close smoothly or evenly.

“Instead they bulge, or prolapse, upward into the left atrium of the heart,” lead researcher Rajiv Mahajan said. “Over the years, there have been several case studies associating mitral valve prolapse with unexplained sudden cardiac death, however, the link had not been confirmed.”

Dr. Mahajan, a cardiologist at the University of Adelaide’s Centre for Heart Rhythm Disorders, said the latest analysis had confirmed the association. “It indicates that the incidence of sudden cardiac death in patients with mitral valve prolapse is significant at 14 in 1000 per year,” he said.

He said mitral valve prolapse was a common condition that in many cases did not cause symptoms or require treatment.

The research, published in the international peer-reviewed journal Heart, also identified features that put people with mitral valve prolapse into the high-risk category for serious cardiac arrhythmias and sudden cardiac death.

Prash Sanders, director of the centre, said one in five sudden cardiac deaths occurred in people with otherwise normal hearts. “This research provides insight into the need for further investigation of patients with mitral valve prolapse and high-risk conditions for serious and life-threatening cardiac arrhythmias,” said Professor Sanders.

He said it was an example of cross-institutional collaboration producing better outcomes.

The mitral valve was named because it resembles a miter — a bishop’s formal headdress.

Mitral valve operations are the fastest growing category of heart surgeries, according to a report in the Annals of Thoracic Surgery.